Commodoer 64 Mechanical Keyboard Direct Replacement.

[iceberg]

Project Description:

This is a direct drop in replacement for Mitsumi keyboard found in Commodore 64 'breabin' style computers. Using Cherry MX (or similar) style panel mount keys and hand wiring the keys to the 8x8 matrix input connector on the Commodore 64 motherboard.


Details:

I have already source 3 Cherry MX locking keys to use as the Shirt-Lock keys so that no additional circuitry is needed. For my first attempt I have sourced 120 Outemu key switches and if everything goes well I will make the second one out of original Cherry MX. The Outemu are significantly cheaper and will be suitable to make sure everything works before I more to more expensive key switches.

References:

tlt(tlt-u2717/) did a similar project(workshop-f7/mec64-keyboard-t4522.html) back in 2013 placing a mechanical keyboard in a 'breadbin' but attaching it to a modern computer. I have talked with tlt and I have the files he provided(more on that below).

The 8x8 key matrix used on the Commodore 64: http://nerdcore.eu/wp-content/uploads/2 ... p4-07l.gif

The keycap converters for Cherry MX to C64 are available on shapeways, they may be in tlt's files as well I haven't looked. I'll be having shapeways print mine as my printer wont print that small. (https://www.shapeways.com/product/UAXHB ... print-v1-1)


Challenges:

I still need to d a lot of work on the plate. I have tlt's cad file for the flat plate, but he has expressed to me there are some minute errors/discrepancies that make it incompatible with the C64c(slim) case. If anyone is good with 3D and would like to help fix the file it would be greatly appreciated. I am thinking of having one 3D printed and if it fits well making a silicon mold and casting a few. The reason for that is 3D printed plastic will not handle the day to day usage that a keyboard plate undergoes. This is only one option as I've been unable to find a fabrication place that can cut and bend the plates. I'm not opposed to that if someone has any suggestions or knows someone.

Hand wiring the keys is going to be a chore. Fortunately all the electronics for the matrix are on the motherboard so no resistors or diodes are needed in wiring the switches. I'll be reusing the connector off an existing Commodore 64 so I don't need to source that.


Open Source/Hardware:

I will make any and all files created available to everyone. I don't know if I will have the ability to make the switch plates available as a group buy till I know what direction I will be taking with it but as I stated ALL files will be available and tlt has original files available as well.

[iceberg]

[RESERVED]

Build Log

[iceberg]

[RESERVED]

F.A.Q.

[iceberg]

I may have found a local company to do a metal frame, but I am still looking for someone good with CAD/3D to make some minor adjustments to the design. I sent tlt's original files to them to evaluate and I should hear back from them by the end of the week.

[tlt]

I made a cable with a connector that could replace the atmega breakout board and connect directly to the C64 motherboard, this was possible because I wired the keyboard matrix like the original keyboard. I think one of them that joined the micro GB used it to get same functionality as you are looking for. The matrix is correctly documented on this page http://www.waitingforfriday.com/?p=470, might be handy when you hand wire it.

[iceberg]

Thanks, that will be incredibly helpful. If this company can do the plate and no one with 3D skills steps up I'll just go with your original as I have no plans right now to put it in a slim.

[tlt]

I just uploaded all the files for the MeC64 project to GitHub

[riddleywalker]

Thanks again tlt for sharing your files. Because I didn't expect you to get back to me so quickly, I have also created a 3d model of a generic mounting plate without the cherrymx key holes. I used an original C64 keyboard mounting plate and measured it with my digital caliper. It was quite fun actually. I will share this on my github as well if either you or iceberg would like to use for whatever. I am currently working on a flat "unfolded" 2-D model for the laser/water cutter and press.

iceberg, I have a friend who has access to all of these metal working machines. If you are interested I can ask him what it would cost to make a few of these for you.

GitHub: https://github.com/theriddleywalker/c64 ... e-template

[iceberg]

iceberg, I have a friend who has access to all of these metal working machines. If you are interested I can ask him what it would cost to make a few of these for you.

GitHub: https://github.com/theriddleywalker/c64 ... e-template

Please do. I was supposed to have someone local get back to me last week and they never did. I'm not one to pester someone so if they are interested they would have gotten back to me.

If we do get one that will work in all the cases I will defiantly make a mold of it and see about casting a few. I don't imagine demand is very high based on responses here but that could change if I let the folks over at Lemon64 know about this. I wont do that till I have one fully built though.

@tlt thanks for making the files available. I wasn't going to share the link without your consent and with you sharing it if t changes again, you have the ability to edit it as opposed to if I posted it.

[riddleywalker]

Hi Iceberg,

I've finished a 2d drawing of the keyboard mounting plate with my own keyhole configuration. I'll be sending this out to my friend and hopefully get something back in a couple days.

I'm in talks with him regarding pricing.

Finally, if you're interested in a copy of my files you can find them at the GitHub link I posted earlier.

All the best!

[iceberg]

Hi Iceberg,

I've finished a 2d drawing of the keyboard mounting plate with my own keyhole configuration. I'll be sending this out to my friend and hopefully get something back in a couple days.

I'm in talks with him regarding pricing.

Finally, if you're interested in a copy of my files you can find them at the GitHub link I posted earlier.

All the best!

Defiantly keep updating. Depending on wha the pricing will be I may be interested in one or two.

[riddleywalker]

Friend will be shipping me the prototype this weekend. Used 14gauge steel. Looks great but may need to switch to aluminum.

[Ir0n]

Lol what a neat project

[iceberg]

Friend will be shipping me the prototype this weekend. Used 14gauge steel. Looks great but may need to switch to aluminum.

Great news! Hopefully you will be able to post some photos. What are the issues that makes you think aluminum will be a better choice?

[riddleywalker]

Hi iceberg,

Aluminum is better when it comes to bending it. Since it's a softer metal, one can get smaller and more precise bends in it.

[riddleywalker]

Hi iceberg,

Update:

I've made a quick video review of my prototype keyboard mount. A few adjustments to the 2d drawing and a switch to aluminum and we should be all set!

Check it out and let me know if you have any suggestions https://vid.me/Je2U

[iceberg]

Hi iceberg,

Update:

I've made a quick video review of my prototype keyboard mount. A few adjustments to the 2d drawing and a switch to aluminum and we should be all set!

Check it out and let me know if you have any suggestions https://vid.me/Je2U

Looking really good. I like how you use the lear case to demo it, very nice touch. What keyset do you have in mind? C64 originals with the adapters, SA Retro or something else? I want to use the original keys with the adapters myself for my first one but maybe something different for another on later down the line.

Thanks for the video.

[riddleywalker]

Hi iceberg,

Thank you. Thinking about using that same set of translucent DCS key caps. Perhaps i'll switch them out for something else, but for the time being they go nicely with my clear case so I'll probably just stick to them.

I'm just about done revising my 2d drawing to compensate for the spacing issues and I've finished adding the keyhole notches I described.

In talks with my friend about the technical details behind bending aluminum. Should have another mount ready in a couple weeks.

I'll keep you all updated.

Here's a picture of the mount with more keys and case.

[Findecanor]

Why are you not using Cherry (or Costar) stabilisers for the space bar? Are those holes dimensioned for the original stabilisers in the C64?

[riddleywalker]

Why are you not using Cherry (or Costar) stabilisers for the space bar? Are those holes dimensioned for the original stabilisers in the C64?

Great question Findecanor. Two reasons: I like the resistance that the key switches provide in that configuration. I also may shorten the width of the space bar and use the space on either side for two additional keys I typically don't need more than about a 2 inch wide space bar.

The key holes are not laid out for the original C64 space bar. The space bar I use is about 1 inch (25.4mm) shorter.

The space bar I measured for is here:

[iceberg]

That is something I meant to ask, it is even possible to use the original C64 keys and layout with yours or it it too different?

[riddleywalker]

That is something I meant to ask, it is even possible to use the original C64 keys and layout with yours or it it too different?

Hi iceberg,

Oh it absolutely is possible. As a matter of fact, the original key layout is what I used as a reference for how much space I would have to lay out the new keys. It all came down to everything fitting properly inside of the case cut outs if that makes sense. In other words, if you take the dimensions of the original C64 keyboard key layout, my keys fit the same area I'll attach an image of what I'm describing.

The attached image shows the workable area that one has to layout whatever key hole configurations you want. This is accurate to about 100th of a millimeter.

[iceberg]

Nice.

[iceberg]

Hi iceberg,

...

The attached image shows the workable area that one has to layout whatever key hole configurations you want. This is accurate to about 100th of a millimeter.

Any updates on your progress?

[riddleywalker]

Hi Iceberg,

Yeah, def. making some progress. Slowly, but progress nonetheless. I've had to adjust some of my dimensions around for the key switches to fit properly. I've also added key stabilizers to a few keys on the keyboard.

Since I last posted, I've had the mounting plate laser cut from aluminum, acrylic, and tomorrow I will have a PETG version. I'm looking for just the right material. Aluminum is a great choice so far. Acrylic is too brittle and I have a feeling PETG will be another great option as well.

I found this site called Ponoko.com. They will laser cut all sorts of materials for you at great prices.

I'll update you once I have made significant progress.

[iceberg]

I'm familiar with Ponoko, but when I talked to them they could not do the bends. Are you having those done yourself or have they recently gotten the machines to do bends?

PETG is good stuff, not quite as strong as ABS but less brittle. I've used it in 3D printing but my printer isn't large enough to print these plates. If I need to increase PETG/PLA rigidness or strength I brush on a coat of this solvent weld I have that helps bond all the print layers together. I don't have the bottle handy so I can't tell you what it is off the top of my head. Aluminum and Carbonfiber are the best bets, but CF is probably quite a bit more exspensive, I havent investigated it though.

[riddleywalker]

Hi iceberg,

I got the PETG prototypes in and all of my fine adjustments have been made. The slightly annoying, yet rewarding thing about this part of my journey was having to convert my sketchup drawing into an Adobe Illustrator EPS.

To answer you question about the bending; I was thinking of building a line bender and doing the bends myself. I'm just not sure yet which material I will choose. My favorite so far is the aluminum. I am having a thicker acrylic version made for me and will see how that goes. Perhaps I can coat the acrylic with something that will make it less brittle?

I like your idea about bonding several layers of the PETG together. I will look into that.

[iceberg]

Acrylic is a pain. There is not much you can to other than moving up to lexan which is a different formulation. Acrylic is only good if you need transparency. Anything you could put on Acrylic to strengthen it would take away it's transparency at which point you might as well be using ABS or PETG sheets. Another options might be carbonfiber.

Sketchup is always a ping because it's not supported by anything and converting it is a hassle when it can be done. I've gotten to the point where I'm only using Inkscape and Blender now.


I've been looking at better ways to attach the C64 keys to MX stems and I have come up with an idea but accuracy is an issue currently. It involves taking cheap keycaps and cutting the sides off then hot gluing them into the C64 caps. Hot glue allows you to restore the C64 caps to normal if you ever need. I can probably model these and have Shapeways 3D print them. They will be more stable then the basic converters tlt made because of the mass. More expensive but more stable.

[Cicada88]

I am interested in at least 2 of these if it gets to production stage--either assembled or unassembled. I need some MX love in my C64 & C64C.

Great work so far!

[iceberg]

I am interested in at least 2 of these if it gets to production stage--either assembled or unassembled. I need some MX love in my C64 & C64C.

Great work so far!

Yes, bot tlt and riddleywalker have both done some amazing work and it's greatly appreciated!